/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.replica.replicaisland;

public final class Lerp {

	public static float lerp(float start, float target, float duration,
			float timeSinceStart) {
		float value = start;
		if (timeSinceStart > 0.0f && timeSinceStart < duration) {
			final float range = target - start;
			final float percent = timeSinceStart / duration;
			value = start + (range * percent);
		} else if (timeSinceStart >= duration) {
			value = target;
		}
		return value;
	}

	public static float ease(float start, float target, float duration,
			float timeSinceStart) {
		float value = start;
		if (timeSinceStart > 0.0f && timeSinceStart < duration) {
			final float range = target - start;
			final float percent = timeSinceStart / (duration / 2.0f);
			if (percent < 1.0f) {
				value = start + ((range / 2.0f) * percent * percent * percent);
			} else {
				final float shiftedPercent = percent - 2.0f;
				value = start
						+ ((range / 2.0f) * ((shiftedPercent * shiftedPercent * shiftedPercent) + 2.0f));
			}
		} else if (timeSinceStart >= duration) {
			value = target;
		}
		return value;
	}
}
